1) Field of the Invention
This invention is related to internally illuminated displays.
2) Discussion of the Related Art
Internally illuminated displays commonly utilize a light box incorporating an array of equally spaced lamps behind a diffuse display panel and border, containing an image to be illuminated. The illumination is accomplished by the placement of lights directly behind the message or image, though lamps can outline the display panel as well. An illuminated display is usually formed of a structure or housing, comprised of either plastic or metal framing, a light device and a diffuse message or image layer. Existing art also uses a mirror in conjunction with the light, to enhance the illumination of the message or image. While the use of the mirror may provide enhancement of a message in short range viewing, its function is rendered ineffective when the display is viewed from great distances.
A beam of light reflects off a mirror at an angle of reflection equal to its angle of incidence. The best conventional mirrors are about ninety-five percent reflective. The rest of the light is lost through absorption. If a light ray strikes a mirror surface, it loses five percent at every “bounce,” leaving reduced illumination at that angle equal to its incident angle. Beams reflected by mirrors do not provide the proper illumination to discern messages or images viewed from long distances.
The disadvantages of current technology are an inability to meet long range viewing requirements, such as those seen on the nations highways and freeways, and at the same time, contend with environmental and other adverse conditions. Current technology is unable to remain visible in direct sunlight, in conditions of low light, darkness or fog, essentially translating into an inability effectively capture and transmit available light.